Head slider suspension assembly load beam having a fundamental mode vibration characteristic in the range of about 2000 hertz to about 4000 hertz

ABSTRACT

A load beam adapted for use in a head slider suspension assembly is shown. The load beam has a generally rectangular shape and includes a member for defining a support arm end and a head/slider loading end. The load beam has a torsional vibration mode characteristic which, upon said load beam being excited by a driving force, produces a fundamental mode vibration in the range of about 2000 hertz to about 4000 hertz and higher order mode vibrations above about 6000 hertz. In the preferred embodiment, the load beam has at least one load rail extending substantially perpendicular therefrom. The at least one load rail can be selected to extend from the load beam in a direction the same as or opposite to the direction in which a head/slider assembly is supported from a head/slider loading end of the load beam.

This is a division of application Ser. No. 07/176,037 filed Mar. 31,1988, which issued as U.S. Pat. No. 4,992,898 on Feb. 12, 1991.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a magnetic head slider suspension assembly forsupporting a head slider in coacting relationship, through an airbearing surface, onto the surface of a rotating magnetic disc, and morespecifically, relates to a magnetic head slider suspension assembly forsupporting a head slider in a single or multi-disc rotating assemblywherein the head slider suspension assembly includes, in the preferredembodiment, a pair of spaced, raised load rails which extend in the samedirection as that of a head slider operatively attached to thehead/slider loading end. In one embodiment, the height of the load railsmay vary from a predetermined height near the head/slider loading end ofthe central arm section to a selected height near the support end. Theload rails define an outer edge that can be of a uniform height, acontinuously tapered edge, a stepped edge, or a combination of a steppededge and tapered edge. The structure of the outer edge permits theadjacent head slider suspension assembly to be moved into an unloadedposition wherein the surface of the load beam, located opposite to thesurface supporting these load rails, coact at the head/slider loadingend. This enables adjacent head sliders to be deflected towards eachother and away from the rotating disc surface during insertion andremoval of the magnetic head slider suspension assembly, having headslider attached thereto, into and from single or multi-disc rotatingassemblies. The amount of deflection at the head/slider loading end isnot influenced by the height of each of the load rails at thehead/slider loading end.

2. Description of Prior Art

The use of a magnetic head slider suspension assembly for loading andunloading a head/slider onto a rotating disc is known in the art. Onesuch magnetic head slider suspension assembly is used in the IBMstandard 3370 Type Suspension Assembly.

Certain of the prior art magnetic head slider suspension assembliesinclude an elongated slider arm having a central arm section, or a loadbeam, and a pair of spaced, uniform height, raised load rails whichextend in a direction away from the head slider operatively attached tothe head/slider loading end. The spacing between co-axially alignedrotating discs, in the prior art multi-disc rotating memory assemblies,are typically in the order of 250 mils (6.35 mm). The above-describedraised load rails, having uniform height of about 30 mils (0.76 mm), areused to provide stiffening of the load beam which supports the headslider suspended therefrom onto the rotating disc surface. In the priorart devices, sufficient spacing exists between adjacent surfaces ofrotating disc to accommodate movement of the head sliders from a "loadedposition", that is where the air bearing surface of a head slider ispositioned to fly over the surface of the disc, away from the discsurface into as "unloaded position", that is where the head slider ispositioned away from the disc surface. The head sliders are positionedin the " unloaded position" during insertion and removal of the headsliders from a multi-disc rotating assembly in order to prevent the headslider from contacting the surface of a magnetic disc. In applicationshaving limited disc spacing, the uniform height, raised load rails ofthe prior art devices limit the degree of movement or rotation of themagnetic head slider suspension assemblies between the "loaded position"and the "unloaded position".

The prior art magnetic head slider suspension assemblies include uniformheight, raised load rails which extend substantially perpendicular fromthe central arm section or load beam, and which extend from the centralarm section in a direction opposite to the direction of a head slideroperatively attached to the head slider loading end. In suchapplications, the load rails function as a stiffening member at alltimes during unloading a rotating disc. During operation the load railsrestrict movement of the head slider loading end of the head slidersupporting the head slider since the head/slider loading end cannot bedeflected any further than the height of the uniform load rails.

It is also known in the art for the head slider suspension assembly tohave a pair of spaced parallel tapered load rails which extend from theelongated arm in a direction opposite to that of the head slideroperatively attached to the head/slider loading end. Such a structurepermits larger displacement of the head/slider loading end where thesame is moved into an "unloaded position". Due to the reduction in theheight of the load rails at the head/slider loading end, a head slidersuspension assembly having tapered height load rails is also smaller insize than the prior art, uniform height load rails.

SUMMARY OF THE PRESENT INVENTION

This invention relates to a new and novel magnetic head slidersuspension assembly which is capable of being used in single ormulti-disc rotating assemblies having co-axially aligned rotating discswhich are designed to have reduced distance or spacing between thesurfaces of adjacent discs as compared to prior art assemblies. Thestructure of the magnetic head slider suspension assembly of the presentinvention permits larger displacement of the head slider when the sameis moved into an "unloaded position." in the preferred embodiment, apair of spaced, load rails extend from the central arm section of theelongated slider arm in the same direction as that of the head slideradapted to be operatively attached to the head/slider loading end.

The magnetic head slider suspension assembly of the present invention isused for loading a head slider having an air bearing surface onto thesurface of a rotating magnetic disc. The magnetic head slider suspensionassembly includes an arm mounting support which Is capable of beingoperatively attached to a loading arm assembly or positioner. Theelongated slider arm is operatively attached at one end thereof, to thearm mounting support. The elongated slider arm extends along anelongated axis and includes a central arm section, or load beam, whichterminates in two ends. The central arm section includes means fordefining at one end thereof a support end having a predetermined widthand the support end is adapted to be operatively coupled to an armmounting support. When the magnetic head slider suspension assembly ofthe present invention is in an "unloaded position" as definedhereinbefore, the central arm section is capable of being deflectedthrough a predetermined acute angle relative to the support end about adeflection section located slightly forward of the support end. Thecentral arm section is generally rectangular in shape and includes meansfor defining at its other end a head/slider loading end having a widthwhich could either be the same or less than the predetermined width ofthe support end. The head/slider loading end is located along theelongated axis of the elongated slider arm and in an opposed spacedrelationship to the support end. The magnetic head slider suspensionassembly includes at least one raised load rail extending substantiallyperpendicular from the central arm section and in the same direction asthat of the head slider operatively attached to the head/slider loadingend. The at least one raised load rail has a length which extends from afirst rail end, commencing forward of the deflection section located, toa second rail end located at about the head/slider loading end. Thefirst rail end of the at least one load rail is located forward of thesupport end has a selected height. The second rail end of at least oneload rail is located adjacent to the head/slider loading end and has apredetermined height which may be different than the selected height. Inthe preferred embodiment, a pair of spaced load rails are used and arepositioned to extend substantially perpendicular from the central armsection in the same direction as that of a head/slider to be supportedfrom the head/slider loading end. The outer edge of the spaced load railmay be of uniform height (e.g. rectangular) or may have a tapered orstepped profile as discussed hereinbelow.

The spaced, raised load rails, positioned on the reverse side of thecentral arm section, function as a stiffening member and are sometimesreferred to herein as "inverted load rails." The head/slider loading endof the central arm section is selected to have a dimension to eliminatepossible interference with the flexure gimbal and head slider adapted tobe attached to thereto.

One disadvantage of the magnetic head slider suspension assemblies ofthe prior art having uniform height load rails is that, the physicalsize and structure thereof does not permit the head/slider loading end,and the head slider affixed thereto, to be deflected beyond a distancedetermined by the height of the uniform load rails. As such, the priorart magnetic head slider suspension assemblies, having head slidersaffixed thereto, cannot be inserted into and removed from the advancedstate-of-the art devices having closer spacing and distances betweenadjacent disc surfaces principally because the head slider will contactthe disc surface, which is highly undesirable.

Another disadvantage of the prior art magnetic head slider suspensionassemblies having uniform height spaced load rails is that the height ofload rails, at the head/slider loading end, limits the displacement ofthe head slider when the same is moved into an "unloaded position". Whenthe spacing between the surfaces of adjacent, rotating disc memories isreduced, say to about 150 mils (3.80 mm), the head sliders are unable tomove a sufficient distance away from the disc surface which could resultin undesirable contact between the disc surface and the head slider,particularly when the head slider suspension assembly is in the"unloaded position".

Certain of the known prior art head slider suspension assemblies havespaced, raised load rails which extend from the elongated slider arm ina direction opposite to that of a head slider operatively attached tothe head/slider loading end wherein the outer edges thereof vary inheight with a smaller height being located adjacent to the head/sliderloading end. This structure permits adjacent head slider suspensionassemblies to be physically moved or displaced over a greater acuteangle, compared to the displacement of a head slider suspension assemblyhaving uniform height load rails, at the head/slider loading end, thatlimitation being due to the physical limitation that the load rails willcontact each other.

In both the uniform height load rail structure and the tapered heightload rail structure of the prior art, the spaced, raised load railsprovide the required stiffness for the head slider suspension assembly.In both prior art head slider suspension assemblies, the load rails aredirected away from the head slider adapted to be attached operatively tothe head/slider loading end and away from the disc surface. As suchthese prior art head slider suspension assemblies add unwanted packageheight to the profile of the head/slider loading end.

Certain improvements have been made in reducing the height or thicknessof single disc drives. As a result of the reduced height of the singledisc drives, the thickness of the head slider suspension assemblybecomes an important factor in the design of such drives. The headslider suspension assembly of the present invention having inverted loadrails can be used in such single disc drives.

Newly developed multi-disc rotating assemblies have increased the numberof discs per drive which results in the reduction of disc-to-discspacing in such assemblies. Heretofore, the limiting factor in thereduction of the disc-to-disc spacing in such drive assemblies has beenthe physical size of the head slider and head slider suspension assemblyin the "Z", or axial direction of the disc package.

For example, one microminimonolithic head slider has height, in the "Z"direction, of 0.034 in. (0.86 mm). This microminimonolithic head sliderhas resulted in the disc-to-disc spacing being reduced to 0.170 in.(4.32 mm) Further reduction of spacing in the "Z" direction has not beenpossible since any reduction in the size of the load rails in the headslider suspension assembly would result in subsequent loss of supportbeam stiffness.

The new and novel head slider suspension assembly of the presentinvention overcomes the above disadvantages of the prior art devices andprovides an improved head slider suspension assembly which can result infurther reduction in the "Z" height of 120 mils (3.04 mm) to 150 mils(3.80 mm), depending upon the head slider chosen, while maintainingsupport beam stiffness.

One advantage of the present invention is that reversed or invertedspaced load rails provide a means for maintaining the required stiffnessof the elongated support arm while providing a smaller dimensionalprofile than prior art head slider suspension assemblies.

Another advantage of the present invention is that the outer edge of theinverted or reversed spaced raised load rails may be continuouslytapered from a predetermined height, near the head/slider end, to aselected height at the support end, wherein the selected height is lessthan the predetermined height, to offer increased load rail-to-discclearance in applications where suspension assembly-to-arm mountingposition is not well controlled. In certain applications, the outer edgemay be of uniform height between the support arm end and the head/sliderloading end.

Another advantage of the present invention is that the reversed orinverted load rails are directed towards the disc surface, placing theload rails physically in a space that was not otherwise used such thatthe load rails extend in the same direction as that of a head slideroperatively attached to the head/slider loading end.

Another advantage of the present invention is that the disc-to-discspacing using the head slider suspension assembly of the presentinvention can be reduced to approximately 0.118 inches (3.00 mm) whilemaintaining the desired support beam stiffness.

Another advantage of the present invention is that one embodiment of theinvention may use a continuous taper formed on the edge of the reversedor inverted spaced rails may have a range of angles in the order ofabout 5 minutes of arc to about 45 minutes of arc.

Another advantage of the present invention is that a pair of invertedspaced raised load rails may be used wherein each of the outer edges ofeach spaced, raised load rail may have one or more stepped edgesintermediate the support end and head/slider loading end. In oneembodiment, the height of the intermediate stepped edge may be equal tothe difference in height between the predetermined height of the loadrails at the support end and the selected height of the head/sliderloading end. The location of the step must be sufficiently inward fromthe support end and towards the head/slider loading end so as to permitsufficient clearance of the head slider suspension assembly from thesurface of the adjacent disc to avoid contact therebetween inapplications with large potential mounting error.

Another advantage of the present invention is that the height of theintermediate stepped outer edge may be less than the difference betweenthe predetermined height of the head/slider loading end and the selectedheight of the support end and that a portion of the outer edge is formedor tapered to compensate for the height differences.

Another advantage of the present invention is the height of the reversedor inverted load rail of the head slider suspension assembly issufficiently large to provide the rigidity required for supporting ahead slider at the support end and the positioning of the load railstowards this disc surface provides the additional spacing required toaccommodate the smaller distances required in advanced minimalizedpackage height design in improved state-of-the-art single or multi-discrotating memory assemblies.

Another advantage of the present invention is that the head/sliderloading end of the central arm section or load beam may be of the sameor substantially the same geometrical dimension, e.g., width, as that ofthe support end. Certain factors may determine the most desirable widthof the head/slider loading end such as, for example, the closeness ofthe track having the smallest radius on a rotating disc nearest the hubof the disc drive. In such applications, the width of the head/sliderloading end would be selected of a dimension to avoid head/sliderloading end-to-hub contact while the head slider suspension assembly ispositioning the head/slider, attached to the head/slider loading endthereof, in an appropriate transducing relationship with the smallestradius track.

Another advantage of the present invention is that the structure of thecentral arm section or load beam has a support end and head/sliderloading end having substantially the same geometrical dimension as thatof the support end making the same generally rectangular in shape. Thus,when the head slider suspension assembly is activated by the discpositioning system to move the head slider to a different positionrelative to the disc, second order or higher mode vibrations areexperienced by the central arm section or load beam but they occur above6,000 hertz. Thus, in the frequency band of the 0 hertz to about 6,000hertz the second or higher order mode vibrations are eliminated. Thisresults in a faster settling time of the head slider suspensionassemblies enabling the disc drive to have faster response times fordata transfer and the elimination of electrical filters heretoforerequired for suppression of second order or higher harmonics from thedriver electronics feedback servo system of the positioning system.

BRIEF DESCRIPTION OF THE DRAWING

These and other advantages of the present invention will become apparentwhen considered in light of the detailed description of the preferredembodiment hereinbelow, which includes the following figures:

FIG. 1 is a top plan view of a magnetic head slider suspension assemblyhaving a support arm with inverted spaced load rails and a flexuregimbal operatively attached thereto, which flexure gimbal having a headslider operatively attached thereto;

FIG. 2 is a side plan elevational view of the head slider suspensionassembly, having a central arm section or load beam, as shown in FIG. 1,operatively attached to an arm mounting support and with the freeposition thereof shown by dashed lines;

FIG. 3 is partial section side plan elevational review of the supportend of the elongated slider arm of FIG. 2 showing the deflectionsection;

FIG. 4 is a top plan view of an unformed head slider suspension assemblycomponent prior to forming the inverted spaced, raised load rails andtwo forms of cable clamps;

FIG. 5 is a side plan elevational view of a formed elongated slider armhaving a uniform height outer edge formed on each of the inverted spacedraised load rails wherein the load rails extend in the same direction asthe head/slider operatively attached to the head/slider loading end;

FIG. 6 is a sectional view of the support end along Section lines 6--6showing the formed cable clamps of FIG. 5;

FIG. 7 is a sectional view of the head/slider end along Section lines7--7 showing the second style of formed cable clamps of FIG. 5;

FIG. 8 is a pictorial representation of an unformed, extended cableclamp located at the support end;

FIG. 9 is a pictorial representation of an unformed deflectable cableclamp located formed in the inverted spaced load rails;

FIG. 10 is a partial pictorial representation of an arm mounting supportoperatively attached to the support end of the head/slider suspensionassembly;

FIG. 11 is a side plan elevation view of the outer edge of an invertedraised load rail having a stepped outer edge, the height of which isequal to the difference in height between the predetermined height ofthe support end and the selected height of the head/slider loading end;

FIG. 12 is a side plan elevation view of an outer edge of an invertedraised load rail having a stepped outer edge and a tapered edge toaccommodate for the difference in height between the predeterminedheight of the support end and the selected height of the head/sliderloading end;

FIG. 13 is a top view of a flexure gimbal adapted to be operativelyattached to the head/slider loading end of a magnetic head suspensionsuspension assembly having inverted spaced load rails for supporting ahead/slider;

FIG. 14 is a side plan view of the flexure gimbal of FIG. 13;

FIG. 15 is a left front plan view of the flexure gimbal of FIG. 13;

FIG. 16 is a partial perspective view of a microminimonolithichead/slider that is operatively attached to one end of the flexure beamof FIG. 13;

FIG. 17 is a front plan pictorial representation of a multi-discrotating memory assembly including an actuator having a support blockfor supporting a plurality of head/slider suspension assemblies in a"loaded position" enabling the head slider to fly on an air bearingsurface over the surface of discs;

FIG. 18 is a graph of amplitude of torsional mode vibrations plotted asa funtion of frequency for a generally triangular shape load beam of aprior art magnetic head suspension assembly; and

FIG. 19 is a graph of amplitude of torsional mode vibration plotted as afunction of frequency for a generally rectangular shape load beam usedin the magnetic head suspension assembly of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 illustrate a formed or assembled magnetic head slidersuspension assembly shown generally by arrow 20. The magnetic headslider suspension assembly 20 is adapted for loading a head slider,having one or more air bearing surfaces, onto the surface of a rotatingmagnetic disc. Typically, the magnetic head slider suspension assemblyhas a head slider affixed thereto, and such an assembly is used in"Winchester" type, rotating magnetic disc systems.

In the preferred embodiment illustrated in FIG. 1, the magnetic headslider suspension assembly includes an elongated load arm 22 having acentral arm section 24 (sometimes referred to herein as a load beam)which extends along an elongated axis 38 of the elongated slider arm 22.The central arm section 24 includes means for defining at one endthereof a support end 26. The support end 26 has a predetermined width,shown as 28, and the support end 26 is adapted to be operatively coupledto an arm mounting support 30. The central arm section 24 furtherincludes means for defining at the other end thereof a head/sliderloading end 32. The central arm section 24 has a deflection section,shown as number 40, which permits or enables the central arm section 24to be deflected about a deflection line within the deflection section40. The deflection section 40 is located slightly forward of the supportend 26, that is towards the head/slider loading end 32. The angle ofdeflection in the "free position", that is the unrestrained positionassumed by the central arm section in the absence of a loading force, isin the range of about 5 degrees to about 25 degrees, and this isillustrated in greater detail in FIG. 2. The preferred angle ofdeflection will vary depending on the desired head slider load forceduring operation.

The width of the head/slider loading end 32, depending upon theapplication, is less than the predetermined width 28 of the support end26. The head/slider loading end 32 is located along the elongated axis38 which extends from the support end 26, through the central armsection 24 to the head/slider loading end 32. The width of thehead/slider loading end 32 may be equal to or less than that of thesupport end 26. The exact width of the head/slider loading end isdetermined by the position of the track closest to the rotating hub of arotating memory. The radius of the track of recorded informationdetermines the distance between that track and edge of the rotating hub.The head slider must be positioned relative to the track by thepositioning system. The width of the head/slider loading end of thecentral arm section 24 must be selected to have a width, when the headslider is positioned over the smallest radius track, such that thehead/slider loading end does not engage or contact the hub. Preferably,the width of the head/slider loading end 32 is slightly less than thewidth of the geometrical dimension of the support end 26 in order toavoid contact with the hub.

As illustrated in FIG. 2, the support end 26 is operatively attached,such as by being welded or by adhesive bonding, to a support arm 30 atinterface 50.

Four extended arcuate-shaped cable clamps 54 are located, two each, oneach side of the support end 26. The extended arcuate-shaped cableclamps 54 are shown in detail in FIG. 8.

A pair of reversed or inverted spaced, raised load rails 42 and 44extend substantially perpendicular from the central arm section 24. Inthe embodiment of FIG. 2, the load rails 42 and 44 have a uniformheight. Each of the load rails 42 and 44 have a length which extendsfrom a first rail end 62 located forward of the deflection section 40.Deflection section 40 is located slightly forward of the support end 26and towards the head/slider loading end 32. The central arm section 24is capable of being deflected downward at an acute angle at thedeflectable section 40 as shown in greater detail in FIG. 3. The firstrail end 62 of each of the load rails 42 and 44 is located slightlyforward or beyond the deflection section 40 so as to not interfere withthe ability of the central arm section 24 to be deflected about thedeflection section 40 at a predetermined minimal acute angle. The loadrails 42 and 44 terminate in a second rail end 64 located adjacent thehead/slider loading end 32. The height of the load rails 42 and 44 atthe second rail ends 64 have a predetermined height, which, in thepreferred embodiment, is in the order of 0.030 mils (0.75 mm). Theheight of the load rails 42 and 44 near the first rail ends 62 has aselected height which may be different than the predetermined height ofthe second rail end 64, but in this embodiment, the heights are uniform.In the preferred embodiment, the uniform height is in the order of 0.030mils (0.75 mm). Thus, the load rails 42 and 44 has its outer edge 68extending from the predetermined height at the second rail end 64 to thesame height at the first rail end 62.

In the preferred embodiment of FIGS. 1 and 2, the pair of spaced, raisedload rails 42 and 44 are positioned to extend from the central armsection 24 in a direction towards the disc surface which is in the samedirection as that of the head/slider supported from the head/sliderloading end 32 as illustrated in FIG. 17. In the structure the raisedload rails 42 and 44 function as stiffening members for a cantileverbeam, e.g. load arm, to provide structural rigidity to the central loadarm section 24. It is envisioned that the structure of each load railcould be different. For example, one load rail could be of uniformheight between the first rail end and second rail end while the otherload rail could have a continuous taper, be stepped, or have some otherstructure which would make the height or the load rail near the supportend equal to or less than the height at the head/slider loading end.

Heretofore, the space located between the head slider suspensionassembly and the disc surface was an unused or dedicated open space. Thedimension of the dedicated open space had to be included in thedisc-to-disc spacing limitations in multi-disc rotating assembly designsand, as such, was one of many limitations which restricted or inherentlylimited the minimum achievable disc-to-disc spacing. Thus, inverting thespaced load rails to place the same in this dedicated open spaceachieved several results; namely: (1) the inverted spaced load rails arepositioned in the dedicated open space to maximize use of the same: (2)the height of the spaced load rails is eliminated as a major limitationin reducing the disc-to-disc spacing, a highly desirable advantage; and(3) the preferred embodiment of the head slider suspension assembly canutilize a pair of inverted spaced load rails having a uniform height, ordiffering heights, to obtain the desired stiffness for the head slidersuspension assembly.

It is envisioned that the central arm section, or the entire head slidersuspension assembly could be fabricated of a material selected to have adesired stiffness such that the desired load beam stiffness could beobtained by the use of one inverted load rail. This is referred toherein as "at least one load rail". The head slider suspension assemblycould be stamped or chemically etched from a stainless steel, such asfor example SST 302/304 which can be acquired from a number ofmanufacturers. However, it is envisioned that the same could befabricated from other suitable materials or alloys, or could befabricated as a laminated structure. The choice of material, structure,stiffness and the like of the head slider suspension assembly would bedetermined by the specific application, specifications of the multi-discrotating assembly and the like, all as is well known to those skilled inthe art.

Each of the inverted load rails 42 and 44 have a plurality ofdeflectable cable clamps 60 integral therewith which are used to hold acable extending from the head/slider loading end 32 to the support end26 as shown pictorially in FIG. 17.

A flexure gimbal 66 having a first end 72 and a second end 70 isoperatively attached to the head/slider loading end 32.

A head slider 74 having one or more air bearing surfaces is adapted tobe operatively attached to the first end 72 of the flexure gimbal 66.The surface of the head slider, which is adapted to be positioned in anopposed spaced relationship to the disc surface, may have one or moreair bearing surfaces depending upon the structure of the entire surface.Typically, air bearing surfaces are formed on load rails which fly themagnetic head slider suspension assembly over the disc surface.Depending upon the design, the surface of the magnetic head/slider hasan air bearing surface, which may be two or more discrete surfaces, allof which function aerodynamically to enable the magnetic head/slider tofly on an air bearing surface formed between the magnetic head sliderand rotating disc.

The second end 70 of the flexure gimbal 66 is operatively attached tothe head/slider loading end 32 to form a cantilever loading beamstructure where in the first end 72 of the flexure gimbal 66 extendsbeyond the head/slider loading end 32 of the central arm section 24. Themagnetic head slider is adapted to flex the flexure gimbal 66 as themagnetic head slider suspension assembly flies, on the air bearingsurface, on the rotating magnetic disc so that the head slidersuspension assembly and the flexure gimbal combined movements permit thehead slider to comply with variations in the disc surface. Thisstructure for operatively attaching the head slider 74 to the flexuregimbal is shown in greater detail in FIG. 16.

FIG. 2 illustrates the assembled magnetic head slider suspensionassembly of FIG. 1 with the arm mounting support 30 operatively attachedto the support end 26. The central arm section 24 is capable of assuminga "free position" about the deflection section 40 shown by load rail42'. When the elongated slider arm is loaded onto the rotating disc, thecentral arm section 24 is deflected along the deflection section 40 intothe "unloaded position" wherein the head/slider loading ends are eitheradjacent to or in contact with each other. The head/slider loading endsare then moved in a direction towards the "free position" until the"loaded position" thereof is reached wherein the central load sectionsare substantially parallel to the disc surface as is shown in greaterdetail in FIG. 17. Design criteria may require a slight angulardisplacement between the support assembly and disc surface of say in theorder of about 20 minutes of arc, and this is deemed to be covered bythe term "substantially parallel".

FIG. 3 illustrates that the deflection section 40 is locatedintermediate to the support end 26 and the first rail end 62 of thespaced, load rail 42. The first rail end 62 is located slightly beyondthe deflection section 40 so as not to interfere with the deflection ofthe central arm section 24 from its "free position", to the "unloadedposition" and ultimately into the "loaded position".

FIG. 4 is an unformed magnetic head slider suspension assembly showingspecifically the elongated slider arm 20 having uniform height loadrails and the relationships between the various components thereof.Specifically when the elongated slider arm 20 is fabricated, the centralarm section 24, the inverted spaced, raised load rails 42 and 44, thesupport end 26, the opening 50, the extended cable support 54, thedeflectable cable clamps 60, as well as other openings are formed in thearm 20. The unformed arm 20 is processed to bend or deflect the spaced,load rails 42 and 44 in the same direction as the direction in which ahead/slider is adapted to be operatively attached to the flexure beam66. The first rail ends 62 are shown to be slightly arcuate in shape andis sufficiently slightly forward of the deflection section 40 to permitmovement of the central arm relative to the support end 26.

FIG. 5 shows a formed elongated slider arm of the unformed elongatedslider arm 20 illustrated in FIG. 4. The reversed or inverted spaced,raised load rail 42 has a first rail end 62 and a second rail end 64. Aplurality of deflectable cable clamps 60 are integral with the load railat several locations in the edge 68.

FIG. 6, which Is a section taken along section line 6--6 of FIG. 5,shows the support end 26 and the position of the extended deflectablecable clamps 54 before receiving a cable.

FIG. 7 is a sectional view showing the relationship between thehead/slider loading end 32, the inverted spaced load rails 42 and 44 andthe shape of the deflectable cable clamp 60 integral with the load rails42 and 44. The formed position of the deflectable cable clamp 60 isshown in phantom as 60' which encloses a cable shown by a dashed circle63.

FIG. 8 illustrates in greater detail the structure of the extendedarcuate-shaped cable clamp 54 formed on support end 26. Specifically,the extended arcuate-shaped cable clamp 54 is formed as part of thesupport end 26 in the following manner. The extended arcuate-shapedcable clamp includes the elongated bendable tang 78 having a fixed endand a deflectable end, with the fixed end thereof integral with thesupport end 26. The deflectable end of the elongated bendable tang 78extends from the support end 26 in a substantially planar directiontherefrom when in the unformed condition as shown in FIG. 8. However,when the elongated bendable tang 78 is formed it is into the shape asshown in FIG. 7. A pair of spaced undercut sections, shown as 76 in FIG.6, are formed in and one on each side of the fixed end of the tang 78.The undercut sections 78 have a depth which approximates aboutone-fourth of the width of the tang 78.

This permits the tang 78, when formed around a cable, to be easilydeflected due to the reduced thickness of the tang 78 at the undercutsections 76. The tang 78 can be deflected into a number of desiredpositions such as beside the support end or under the elongated sliderarm to hold the cable in a desired located relative to the elongatedslider arm.

In the preferred embodiment, the arcuate-shaped bendable tang 78 has awidth in the order of 30 mils (0.60 mm) and a selected length whichenables the tang 78 to be deflected in a radius of curvature of about 10mils (0.20 mm). The deflection or forming commences at dashed line 77.The radius of curvature is illustrated in FIG. 6. The arcuate-shapedtang 78 cooperates with the undercut sections 76 to permit easypositioning thereof, when attached to a cable, relative to the supportend.

FIG. 9 illustrates the structure of the deflectable cable clamps 60which are integral with the load rails 42 and 44. The deflectable cableclamp 60 includes a tang 82 which has a pair of undercuts 86 formed oneach side thereof defining a circular periphery which forms an opensection 84 at the juncture of where the tang 82 is integral with theload rail; e.g., load rail 42.

In the preferred embodiment, the undercuts 86 have a depth whichapproximates the radius into which the tang is capable of beingdeflected. This results in the top of the deflected tang being atsubstantially the same level as the top of the support structure, whichin the preferred embodiment is the outer edge of the load rail. Theprofile of the deflected tang to be substantially the same as that ofthe supporting structure, which in the preferred embodiment, is the loadrail.

FIG. 10 illustrates support end 26 operatively attached to the armmounting support 30. The support end 26 is welded or adhesive bonded tothe plate section of arm mounting support 30 as is illustrated by weldspots 96. Opening 50 is used as an alignment means to ensure properpositioning of the support end 26 to the arm mounting support 30.

FIG. 11 illustrates a different embodiment of the magnetic head slidersuspension assembly of FIGS. 1 through 4. In the embodiment of FIG. 11.The pair of inverted spaced, raised load rails, shown generally as 142,includes a means for defining a stepped, outer edge, wherein the step146 is located away from the head/slider loading end. The head/sliderloading end has a height, shown generally in 150. The height of the step146 is equal to the difference between the predetermined height of thespaced raised load rails at the head/sliding loading end, having aheight 150, and a selected height of the rails at the support end shownby selected height 144. The selected height 144 is less than thepredetermined height 150 such that the height of the outer edge 148 nearthe head/slider loading end is greater than the height 144 near thesupport end.

FIG. 12 illustrates a magnetic head slider suspension assembly of yetanother alternate embodiment compared to that of FIGS. 1 through 4 andFIG. 11. The pair of inverted spaced, raised load rails, shown generallyin 164, include means for defining a combination of uniform heightsections and a stepped-tapered outer edge section of a load rail,wherein the step 172 or beginning of the taper is located away from thehead/slider loading end having a height 150. The height of the step 172can be less than the predetermined height 150 at the head/slider loadingend with a smaller selected height 144 at the support end. Thepredetermined height 150 at the head/slider loading end is greater thanthe selected height 144 such that the height of the outer edge 176 nearthe head/slider loading end is greater than the height thereof near thesupport end. As a result, the portion of the outer edge which extendsfrom the step 172 to the support end, is tapered at an angle tocompensate for the difference in height between the height of the step172 and the predetermined height 150 at the support end.

It is envisioned that one or more steps could be located intermediatethe support end and the head/slider loading end. For example, the heightof the outer edge could be adjusted by use of a single step, or aplurality of steps, or at least one step together with a tapered edge orany combination thereof. As illustrated in FIGS. 11 and 12, the loadrails include means for defining an outer edge wherein the commencementof a sloping section thereof is located away from the head/sliderloading end. The outer edge that extends from the height of thehead/slider loading end may be formed to have a shape to compensate forthe difference in height between the selected height of at the supportend and the predetermined height at the head/slider loading end.

FIG. 13 illustrates the details of the structure of the flexure gimbal66 illustrated in FIG. 11. The flexure gimbal 66 has first end 70 whichis adapted to be operatively attached to the head/slider loading end 32of the head slider suspension assembly as shown in FIG. 1. The flexuregimbal 66 is preferably operatively attached In the vicinity of opening180 to the head/slider loading end. The second end 72 of the gimbal beamhas a deflectable, elongated leaf spring member 182 which is integralwith and supported by the second end 72. The deflectable, elongated leafspring member 182 is essentially a cantilever beam structure and is usedto support a magnetic head slider for flying on an air bearing surfaceover the surface of a rotating disc. A dimple 186 is formed in thedeflectable, elongated leaf spring 182 which is used to facilitate thesupporting of the magnetic head slider from the flexure beam as isillustrated in FIG. 16.

FIG. 14 shows the relationship between the main structure of theflexible gimbal 66 and the deflectable elongated leaf spring 182. Theleaf spring 182 can be fabricated to be integral with the main structureof the flexure gimbal 66, and this can be accomplished by stamping orchemical etching of the flexure gimbal 66. It is also envisioned thatthe main structure of the flexible gimbal 66 could be fabricated as oneelement and the deflectable, elongated leaf spring 182 as a secondelement. The two elements could then be fabricated into a flexure gimbalsubassembly to form the flexure gimbal.

FIG. 15 is a left end view of the flexure gimbal of FIG. 14 showing thatan indentation 190 is formed in the second end 72 such that thedeflectable, elongated leaf spring 182 is slightly separated from themain structure of the flexure gimbal 66 and independently moveable withrespect to the main structure.

Any appropriate head slider can be used with the magnetic slidersuspension assembly described hereinabove. FIG. 16 illustrates thepreferred embodiment of a magnetic head slider, shown generally as 200,which is used with the magnetic head slider suspension assembly asdescribed herein. The magnetic head slider 200 is operatively attachedto the flexure gimbal 66, which is, in turn, operatively attached to thehead/slider loading end 32 of the magnetic head slider suspensionassembly as shown in FIG. 1. In the preferred embodiment, the magnetichead slider is bonded to or attached to the underside of leaf spring182. Typically, an epoxy or adhesive is used to securely bond or attachthe magnetic head slider to the leaf spring. Depending upon theapplication, an electrically conductive or non-conducive adhesive or thelike may be used. If an epoxy is used, the epoxy can be cured usingknown state of the art curing techniques such as, for example, heatingin an oven (e.g. oven curing) or by exposing to UV radiation. Theselection of an appropriate epoxy is well known to persons skilled inthe art, and need not be discussed in detail herein. The magnetic beadslider assembly 200 includes a slider body 204 having an air bearingsurface 206 and an opposed, spaced, parallel surface 210.

The magnetic head slider 200 includes a "C" shaped magnetic core 216which is bonded to the slider loading 204. The arm of the "C" shapedmagnetic core 216 nearest the air bearing surface 206 functions as oneof the two magnetic pole pieces and the trailing edge 214 of the sliderbody 204 is formed to function as the other pole piece as describedhereinbelow.

The "C" shaped magnetic core includes coil windings 218 having leads 220which electrically connected to leads of a cable which pass from thehead slider loading end 32, through a tubular member to the support end26 of the head/slider flexure as shown in FIG. 17.

By utilizing the teachings of the present invention, the magnetic headslider assembly, as a separate component, has an overall height ofapproximately 0.034 inches (0.86 mm) which allows for a lower profile. Alower profile, that is the dimension in the "z-height" directionassociated with a rotating magnetic disk, is highly desirable when themagnetic head slider assembly is attached to and used with a magnetichead slider suspension assembly. Also, the magnetic head slider assemblyusing the teachings of this invention has a smaller physical size, lowermass, and a more efficient core geometry. Also, the "C" shaped magneticcore can be easily bonded to the magnetic head slider by using theteachings of this invention.

A transverse slot 212 is formed in the trailing edge 214 of the magnetichead slider, body 204, as shown in FIG. 16, to control the angles of theelements defining the pole piece. Specifically, the internal core apexangle can be increased to approximately 90° total. Preferably, the 90°angle is split approximately equally, i.e. each pole piece being about45°, between the lower end of the "C" shaped magnetic core and the lowerouter edge which defines the transverse slot. By increasing the internalcore apex angle, a decrease in core apex flux leakage is obtained, whichdirectly reduces the core apex flux leakage losses and decreases thehead inductance. As a result of the above geometry, an increase in coreread efficiency and write field strength is obtained. The addition of ahorizontal slot 212 to the slider trailing edge 214 physicallyinterposes a larger air gap between the trailing edge of the magnetichead slider, on one hand, and on the other hand, the lower leg of the"C" shaped magnetic core.

As a result, the core efficiency is increased and a portion of theactual core opening or cavity is moved into the slider body, whichfacilitates easier coil winding as described herein.

Two spaced vertical slots 222 are formed into the trailing edge 214 ofthe magnetic head slider, body 204, one on each side of and adjacent tothe "C" shaped magnetic core. The vertical slots 222 are formed by theremoval of magnetic material of the slider located in the vicinity ofthe "C" shaped magnetic core. The so formed vertical slots 222 furtherreduces flux leakage losses and parasitic inductance between themagnetic core and the slider. Also, the vertical slots 222 facilitatecoil winding due to the addition of space or a larger cavity which ispresent within the area of the magnetic core itself.

FIG. 17 illustrates a typical rotating disc memory assembly havingspaced discs 250 and 252. An actuator or positioner, shown generally as254, includes means for supporting the magnetic head slider suspensionassemblies 256 from a support block, of which support block 258 istypical. The suspension assemblies 256 each have a magnetic head slider,shown generally as 260, operatively attached thereto as describedhereinabove. As such, the magnetic head sliders 260 fly, on its one ormore air bearing surfaces, over the surface of discs 250 and 252. Themagnetic head slider suspension assemblies 256 can be moved from the"loaded position", as illustrated on FIG. 17, to an "unloaded position"by displacement of the magnetic head slider suspension assemblies 256 inthe direction away from the disc surface. When the magnetic head slidersare moved into the "unloaded position", the entire actuator 254 is thenmoved relative to the disc 250 and 252 to transport the magnetic headslider suspension assemblies 256 away from the discs 250 and 252.

Magnetic head slider suspension assemblies have certain mass andstiffness and the central arm section or load beam thereof exhibitsvarious modes of torsional and other vibrations during track-to-trackpositioning. In the frequency bandwidth of interest, say 0 hertz to6,000 hertz, the load beam may have in the order of 5 to 10 vibrationmodes. Each vibration mode is discrete, has a specific mode shape, and afrequency of oscillation associated therewith. The mode of lowestfrequency vibration is the "fundamental mode," and the higher frequencyvibration modes, termed harmonic vibration modes, are referred to as"higher order modes."

The prior art head slider suspension assemblies including specificallythe standard mini-suspension assemblies, such as for example, the IBM3370 type head slider suspension assembly or the Whitney type suspensionassembly, have a load beam which is generally triangular-shape whereinthe head/sliding loading end has a substantially smaller geometricaldimension than the support end.

In a disc drive system using head slider suspension assemblies, the loadbeam portion of the head slider suspension assembly exhibits modevibrations when its is excited into vibration by a driving forceresulting from the track-to-track motion of the positioning system.Typically, the mode shapes of vibrations that are activated by thepositioning system are those modes which are "torsional" in shape.

In such disc drive systems, the electronics and a feed back servo loopare used to maintain track-to-track position between the head slider anddisc. Electrical filters having a selected bandwidth are normallyincluded in the feedback servo loop electronics to remove spurioussignals produced by the fundamental and higher order mode vibrations ofthe head slider suspension assembly. Absent such electronical filters,the servo feedback loop would experience overloading during the shortperiods of time when the vibrations are occurring. As a result, it isnecessary to provide some settling time for the head slider suspensionassembly before data transfer commences.

The drive speed of the positioning system in a typical disc drive systemis selected to accommodate vibrations for both the: (i) fundamentalmode; and (ii) second order or higher order modes. This is the majorfactor which determines the "settling time" and response time for datatransfers in a disc drive system.

In the prior art (or conventional) head slide suspension assembly, afundamental mode vibration will occur at approximately 2,000 hertz to3,000 hertz with higher order modes vibrations occurring at variousfrequencies above that of the fundamental mode, usually in the 3,000hertz to 6,000 hertz range.

FIG. 18 depicts a graph of the results of vibration testing for agenerally triangular shaped load bearing arm of the IBM 3370 type orWhitney type suspension assembly. The graph of FIG. 18 plots therelative amplitude of vibrations of a generally triangular-shaped loadbeam as a function of frequency in hertz (hz). Curve 262 shows that theamplitude of vibrations of the triangular-shaped load beam decrease from0 hertz to about 1,000 hertz and then the load beam experiences harmonicvibrations at about 2,000 hertz to about 2,700 hertz as depicted bypeaks 264 and 266. Above about 2,700 hertz to about 6,000 hertz, theamplitude of the higher order modes of vibration decreases from theamplitude of peak 266, through the 3,000 hertz and 4,000 hertz frequencyrange to a substantially uniform amplitude at about 5,000 hertz to 6,000hertz.

FIG. 19 shows a graph of the amplitude of vibrations of a generallyrectangular shaped load beam plotted as a function of frequency (hz) forthe head slider suspension assembly of the present invention. As isdepicted by curve 270, the head/slider suspension assembly experiencessubstantially the same vibration characteristics as the prior artsuspension assembly to about 2,000 hertz where the fundamental mode ofvibration occurs, and that condition is shown by peak 272. Thereafter,the vibration amplitude drops rapidly such that a substantially uniformamplitude is experienced starting about 3,000 hertz up to about 6,000hertz,

In the load beam structure of the present invention, the above-describedimprovement appears to result from the torsional stiffness of the loadbeam due to its generally rectangular shape. It further appears that theincreased `torsional` stiffness results in the modes of vibrations,other than the fundamental mode, being shifted to higher frequencies.Specifically, in the present invention, the torsional stiffness of theload beam has shifted the second torsional mode vibrations from therange of about 3,000 hertz to about 4,000 hertz range, associated withthe prior art suspension systems, up to a frequency greater than 6,000hertz.

Disc drive positioning systems servo feedback loops typically do notrespond to frequencies above 6,000 hertz, and the bandwidth of concernis in the 0 hertz to about 6,000 hertz range. As such, electronicfiltering of the servo loop driving electronics above the 6,000 hertzrange is not required.

The structure of the load beam of the present invention does exhibitfundamental mode vibration, and this does require electrical filteringin the servo loop feedback electronics in the 2,000 to 4,000 hertzrange. However, elimination of vibrations of the higher order modes fromthe 4,000 hertz to 6,000 hertz range, in turn, eliminates the need forelectronic filters above the 4,000 hertz range.

The utility of this feature of the invention is that the cost forelectronic filtering is reduced, and the disc drive system has fasterdisc drive data access due to faster head slider positioning and areduction in settling time.

It is well known in the rotating magnetic disc memory storage system artthat the industry is advancing to have a tighter packing density and toreduce the disk-to-disk spacing. As a result, magnetic head slidersuspension assemblies must have a lower profile. The reduction in heightof the magnetic head flexure, when coupled with reduction in height ofthe improved magnetic head slider suspension assembly of the presentinvention, permits use of low profile magnetic head sliders resulting inimproved rotating disk memory systems. Typically, the "z-height", thatis the distance between the air bearing surface(s) of the magnetic headslider and the mounting surface of the support, are in the order of0.059 inches (1.49 mm). The combination of the "Z-height" of themagnetic head slider, the required arm thickness and the suspensionassembly results in about 200 mils (5.06 mm) disc-to-disc spacing in theprior art devices. By reducing the overall height of the magnetic headslider suspension assembly of the present invention, a substantialdecrease in disk-to-disk spacing can be obtained. Thus, the use of themagnetic head slider having a low profile as that of the presentinvention can he used with improved magnetic head suspension assembliesalso having a low profile. The magnetic head slider, in combination witha magnetic head slider suspension assembly, having a lower profile,results in an improved magnetic head slider suspension assembly whichcan be used to provide the additional spacing advantage required foraccommodating the smaller distances in the improved state-of-the-artrotating single or multi-disk rotating memory systems.

What is claimed is:
 1. A load beam adapted for use in a head slidersuspension assembly comprisinga load beam having a generally rectangularshape and including means for defining a support arm end and ahead/slider loading end, said load beam having a torsional vibrationmode characteristic which, upon said load beam being excited by adriving force, produces a fundamental mode vibration in the range ofabout 2,000 hertz to about 4,000 hertz and higher order mode vibrationsabove about 6,000 hertz.
 2. The load beam of claim 1 wherein thefundamental mode vibration occurs at about 2,000 hertz and the higherorder mode vibrations occur above 6,000 hertz.
 3. The load beam of claim1 wherein said load beam includes means for defining at one end thereofa support end which is adapted to be operatively coupled to an armmounting support; anda raised load rail extending substantiallyperpendicular from said load beam, said raised load rail having a lengthwhich extends from a first rail end located near said one end to asecond rail end located about at a head/slider loading end which ispositioned opposite to said one end.
 4. The load beam of claim 3 whereinthe height of the raised load rail is the same at both said first railend and said second rail end.
 5. The load beam of claim 3 wherein theheight of the first rail end is a predetermined height and the height ofthe second rail end is a selected height which is one of a height equalto and less than said predetermined height.
 6. The load beam of claim 3further comprisinga second raised load rail extending substantiallyperpendicular from said load beam in the same direction as and spacedfrom said raised load rail, said raised load rail and said second raisedload rail defining a pair of substantially parallel spaced raised loadrails.
 7. The load beam of claim 6 wherein said raised load rails extendin a selected direction from said load beam and wherein said selecteddirection is in a direction opposite to the direction in which ahead/slider assembly is supported from said head/slider loading end. 8.The load beam of claim 6 wherein said raised load rails extend in aselected direction from said load beam and wherein said selecteddirection is in the same direction in which a head/slider assembly issupported from said head/slider loading end.
 9. The load beam of claim 6wherein the heights of said first rail end and second rail end on eachof said raised load rails are the same.
 10. The load beam of claim 6wherein the height of the first end on each of said raised load rails isa predetermined height and the height of the second rail end on each ofsaid raised load rails is a selected height which is one of a heightequal to and less than said predetermined height.
 11. The load beam ofclaim 6 wherein each of said raised load rails has an outer edge whichextends from said first rail end to said second rail end, said loadrails including means defining a tapered outer edge along a portion ofeach of said load rails.
 12. The load beam of claim 6 wherein each ofsaid raised load rails has an outer edge which extends from about saidsupport end to about said head/slider loading end, said load railsincluding means for defining a stepped outer edge wherein the step islocated away from the head/slider loading end and the height of the stepis equal to the difference between a predetermined height of saidspaced, raised load rails at said head/slider loading end and a selectedheight at said support end, said selected height being greater than saidpredetermined height such that the height of said outer edge near thehead/slider loading end is less than the height thereof near saidsupport end.
 13. The load beam of claim 6 wherein each of said raisedload rails has an outer edge which extends from about said support endto about said head/slider end, said load rails including means fordefining a tapered outer edge wherein the tapered outer edge commencesat a point which is located away from the head/slider loading end suchthat the height of said outer edge near the head/slider loading end is apredetermined height which is greater than the height thereof near saidsupport end which is a selected height and wherein the outer edge ofeach said load rail extending from said head/slider loading end to saidsupport end is tapered at an angle to compensate for the difference inheight between the selected height at said support end and thepredetermined height at said head slider loading end.
 14. The load armof claim 3 further comprisingan arm mounting support operatively coupledto said support end.
 15. The load beam of claim 3 further comprisingaflexure gimbal for supporting a head/slider having an air bearingsurface having a first end and a second end, said first end beingoperatively attached to said head/slider loading end of said load beamforming a cantilever loading beam with said second end of the flexuregimbal extending beyond the head/slider loading end of said load beam.16. The load beam of claim 3 further comprisinga flexure gimbal having afirst end and second end, said first end being operatively attached tothe head/slider loading end and said second end having an elongated leafspring operatively attached thereto; and a head/slider having an airbearing surface operatively attached to the elongated leaf spring. 17.The load beam of claim 16 wherein the head/slider extends in the samedirection as said raised load rail.
 18. The load beam of claim 16wherein the head/slider extends in a direction opposite to the raisedload rail.
 19. A magnetic head slider suspension assembly comprisinganelongated slider arm which extends along an elongated axis and whichincludes a load beam having a generally rectangular shape and includingmeans for defining a support arm end and a head/slider loading end, saidload beam having a torsional vibration mode characteristic which, uponsaid load beam being excited by a driving force, produces a fundamentalmode vibration in the range of about 2,000 hertz to about 4,000 hertzand higher order mode vibrations above about 6,000 hertz, said load beamfurther including means for defining at one end thereof a support endhaving a predetermined width and which is adapted to be operativelycoupled to an arm mounting support and defining at its other end ahead/slider loading end having a width which is slightly less than thepredetermined width of said support end, said head/slider loading endbeing located along said elongated axis and in an opposed, spacedrelationship to said support end; and a pair of spaced, raised loadrails extending substantially perpendicular from said load beam and in aselected direction relative to that of a head slider adapted to besupported from the head/slider loading end, each of said raised loadrails having a length which extends from a first rail end located nearsaid support end to a second rail end located slightly forward of saidhead/slider loading end, each first rail end of each said pair of saidload rails having a selected height and each second rail end of each ofsaid pair of load rails being located adjacent said head/slider loadingend having a predetermined height which is one of equal to and greaterthan said selected height.
 20. The load beam of claim 19 wherein thefundamental mode vibration occurs at about 2,000 hertz and the higherorder mode vibrations occur above 6,000 hertz.